Extracorporeal life support system

Abstract

The present invention provides a method, system, and apparatus that can substantially reduce the recirculation of venovenous extracorporeal membrane oxygenation (VV ECMO) associated with the two-site, single-lumen cannulation approach. Actively-controlled flow regulators comprising balloon, occluder and reservoir can be individually or collectively equipped on the drainage and/or infusion cannulas to accomplish the goal of maximizing VV ECMO support efficacy. Three specific embodiments are introduced to illustrate the practical enforcement of the proposed blood flow control in reference to the heart rhythm, aiming at achieving the maximal reduction of oxygenated blood flow recirculating back to the VV ECMO circuit.

The invention claimed is: 
     
       1. An extracorporeal life support system comprising:
 a blood pump and an oxygenator disposed outside a patient's body; 
 a drainage cannula assembly disposed in superior vena cava or inferior vena cava to receive deoxygenated blood, comprising at least one of a drainage balloon, a drainage occluder and a drainage reservoir that are employed and actuated in accordance with the patient's heart rhythm, wherein the drainage balloon is inflated or deflated to control venous return blood flow, the drainage occluder is compressed or relaxed to control blood drainage into the extracorporeal life support system, and the drainage reservoir is actuated together with the drainage occluder to result in a continuous blood pump flow; and 
 an infusion cannula assembly disposed opposite to the drainage cannula assembly in either the superior vena cava or the inferior vena cava, the infusion cannula assembly being employed to deliver oxygenated blood flow back to the patient's circulation, 
 wherein the drainage cannula assembly comprises a drainage cannula, a drainage air catheter and a drainage Y-connector, and the drainage air catheter is connected to the drainage balloon and physically separated from the drainage cannula, wherein the drainage cannula comprises a cannula tip and a plurality of drainage holes distributed at one end of the drainage cannula, wherein the drainage cannula is coupled to a first arm of the drainage Y-connector, and a plug is equipped on a second arm of the drainage Y-connector for receiving the drainage air catheter insertion. 
 
     
     
       2. The extracorporeal life support system as claimed in  claim 1 , wherein the drainage cannula assembly comprises two fluid passages, one fluid passage is able to transmit blood, another fluid passage is connected to the drainage balloon to drive the drainage balloon inflation or deflation, and the two fluid passages are separated and are not fluid communicated to each other. 
     
     
       3. The extracorporeal life support system as claimed in  claim 2 , wherein the drainage cannula assembly comprises a sealed cannula end disposed on one end of the drainage cannula assembly, and a plurality of drainage holes disposed on a side wall of the drainage cannula assembly and near the sealed cannula end. 
     
     
       4. The extracorporeal life support system as claimed in  claim 1 , wherein the drainage air catheter comprises an inner tube and an outer tube, the outer tube is used for pneumatic control of the drainage balloon inflation or deflation, and the inner tube is filled with a liquid for blood pressure sensing. 
     
     
       5. The extracorporeal life support system as claimed in  claim 1 , wherein the patient's heart rhythm is acquired from an electrocardiographic signal.